ARM: OMAP3: PM: Move IO Daisychain function to omap3 prm file

Since IO Daisychain modifies only PRM registers, it makes sense to move
it to PRM File. Also changed the timeout value for IO chain enable to
100us and added a wait for status disable at the end.

Thanks to Nishanth Menon <nm@ti.com> for contributing a fix to the
timeout code waiting for WUCLKOUT to go high.

Signed-off-by: Vishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Reviewed-by: Rajendra Nayak <rnayak@ti.com>
[paul@pwsan.com: renamed omap3_trigger_io_chain() to better describe the
 end result and to match other PRM functions; removed
 omap3_disable_io_chain(); moved MAX_IOPAD_LATCH_TIME to prcm-common as it
 will also be used by the OMAP4 code; removed unnecessary barrier;
 added kerneldoc; added credit for fix from Nishanth]
Signed-off-by: Paul Walmsley <paul@pwsan.com>

diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 6d7f0d8a310365fffd67ed6f3b32c19d07de5e36..9d6cb7cc94ab3f7d436e9038bfd640d3d3e2c203 100644 (file)
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -72,34 +72,6 @@ static struct powerdomain *mpu_pwrdm, *neon_pwrdm;
 static struct powerdomain *core_pwrdm, *per_pwrdm;
 static struct powerdomain *cam_pwrdm;
 
-static void omap3_enable_io_chain(void)
-{
-       int timeout = 0;
-
-       omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
-                                  PM_WKEN);
-       /* Do a readback to assure write has been done */
-       omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN);
-
-       while (!(omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST) &
-                OMAP3430_ST_IO_CHAIN_MASK)) {
-               timeout++;
-               if (timeout > 1000) {
-                       pr_err("Wake up daisy chain activation failed.\n");
-                       return;
-               }
-       }
-       omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
-                                    PM_WKEN);
-
-}
-
-static void omap3_disable_io_chain(void)
-{
-       omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
-                                    PM_WKEN);
-}
-
 static void omap3_core_save_context(void)
 {
        omap3_ctrl_save_padconf();
@@ -305,7 +277,7 @@ void omap_sram_idle(void)
             core_next_state < PWRDM_POWER_ON)) {
                omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_MASK, WKUP_MOD, PM_WKEN);
                if (omap3_has_io_chain_ctrl())
-                       omap3_enable_io_chain();
+                       omap3xxx_prm_reconfigure_io_chain();
        }
 
        pwrdm_pre_transition();
@@ -382,12 +354,9 @@ void omap_sram_idle(void)
        /* Disable IO-PAD and IO-CHAIN wakeup */
        if (omap3_has_io_wakeup() &&
            (per_next_state < PWRDM_POWER_ON ||
-            core_next_state < PWRDM_POWER_ON)) {
+            core_next_state < PWRDM_POWER_ON))
                omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_MASK, WKUP_MOD,
                                             PM_WKEN);
-               if (omap3_has_io_chain_ctrl())
-                       omap3_disable_io_chain();
-       }
 
        clkdm_allow_idle(mpu_pwrdm->pwrdm_clkdms[0]);
 }

diff --git a/arch/arm/mach-omap2/prcm-common.h b/arch/arm/mach-omap2/prcm-common.h
index 6da3ba483ad118ea0b0e8082fa9e5e3417635465..fca23cbea708798a1adca967041cbfe1d51b2d3a 100644 (file)
--- a/arch/arm/mach-omap2/prcm-common.h
+++ b/arch/arm/mach-omap2/prcm-common.h
@@ -410,6 +410,14 @@
  */
 #define MAX_MODULE_HARDRESET_WAIT              10000
 
+/*
+ * Maximum time(us) it takes to output the signal WUCLKOUT of the last
+ * pad of the I/O ring after asserting WUCLKIN high.  Tero measured
+ * the actual time at 7 to 8 microseconds on OMAP3 and 2 to 4
+ * microseconds on OMAP4, so this timeout may be too high.
+ */
+#define MAX_IOPAD_LATCH_TIME                   100
+
 # ifndef __ASSEMBLER__
 extern void __iomem *prm_base;
 extern void __iomem *cm_base;

diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.c b/arch/arm/mach-omap2/prm2xxx_3xxx.c
index 9ce765407ad55d5ac9190af77cdb48338c338752..7d62bd654dbeac9a596a9f7a366e742d95fc7385 100644 (file)
--- a/arch/arm/mach-omap2/prm2xxx_3xxx.c
+++ b/arch/arm/mach-omap2/prm2xxx_3xxx.c
@@ -301,6 +301,37 @@ void omap3xxx_prm_restore_irqen(u32 *saved_mask)
                                OMAP3_PRM_IRQENABLE_MPU_OFFSET);
 }
 
+/**
+ * omap3xxx_prm_reconfigure_io_chain - clear latches and reconfigure I/O chain
+ *
+ * Clear any previously-latched I/O wakeup events and ensure that the
+ * I/O wakeup gates are aligned with the current mux settings.  Works
+ * by asserting WUCLKIN, waiting for WUCLKOUT to be asserted, and then
+ * deasserting WUCLKIN and clearing the ST_IO_CHAIN WKST bit.  No
+ * return value.
+ */
+void omap3xxx_prm_reconfigure_io_chain(void)
+{
+       int i = 0;
+
+       omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
+                                  PM_WKEN);
+
+       omap_test_timeout(omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST) &
+                         OMAP3430_ST_IO_CHAIN_MASK,
+                         MAX_IOPAD_LATCH_TIME, i);
+       if (i == MAX_IOPAD_LATCH_TIME)
+               pr_warn("PRM: I/O chain clock line assertion timed out\n");
+
+       omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
+                                    PM_WKEN);
+
+       omap2_prm_set_mod_reg_bits(OMAP3430_ST_IO_CHAIN_MASK, WKUP_MOD,
+                                  PM_WKST);
+
+       omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST);
+}
+
 static int __init omap3xxx_prcm_init(void)
 {
        if (cpu_is_omap34xx())

diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.h b/arch/arm/mach-omap2/prm2xxx_3xxx.h
index 491c72dd20a06037461e4f34469d463428f65f6d..a8c946f318ab798b5abeb79dbe9c3349324f8b17 100644 (file)
--- a/arch/arm/mach-omap2/prm2xxx_3xxx.h
+++ b/arch/arm/mach-omap2/prm2xxx_3xxx.h
@@ -317,6 +317,8 @@ extern u32 omap3_prm_vcvp_read(u8 offset);
 extern void omap3_prm_vcvp_write(u32 val, u8 offset);
 extern u32 omap3_prm_vcvp_rmw(u32 mask, u32 bits, u8 offset);
 
+extern void omap3xxx_prm_reconfigure_io_chain(void);
+
 /* PRM interrupt-related functions */
 extern void omap3xxx_prm_read_pending_irqs(unsigned long *events);
 extern void omap3xxx_prm_ocp_barrier(void);